Three- and four-wheeled human powered recumbent cycles are well known. They have many advantages over traditional bicycles, such as a more comfortable position for the driver, more stability and safety on the road, greater pedaling force and some others. But at the same time, this type of vehicles has a few disadvantages.
The first disadvantage relates to their large size. Like a personal vehicle, recumbent cycles are usually used for short periods, the rest of the time the vehicle must be stored some place. In the house it can be a garage or shed, but it is very difficult to store such a vehicle in a residential building. To transport this vehicle by a car is also difficult. U.S. Pat. No. 5,544,906 discloses a three-wheel cycle stored in an upright position and U.S. Pat. No.5,145,196 describes a collapsible tricycle; but most existing patents for recumbent cycles do not mention anything about the storage and carriage problems. It would be advantageous to provide a vehicle, which can be folded and disassembled as well.
Compared to standard bicycles, driving a three- or four-wheeled cycle on a road is uncomfortable because roads usually slope away from the middle towards the side and the seat is not straight. Also, on turning, the centrifugal force tends to shift the rider's body to the side, which requires an extra effort from the driver to keep the balance. To solve these problems, some patents disclose a vehicle with some type of leaning system. For example, the cycle disclosed in U.S. Pat. No. 6,402,174B1 has a leaning seat and all leaning wheels while the vehicles disclosed in U.S. Pat. Nos. 4,432,561 and 5,568,935 have a leaning seat and just one leaning wheel. In all of these cycles the leaning is controlled by the effort of hands, which requires the driver's constant attention and which increases the strain on the driver's hands and arms. For comfortable riding it would be advantageous to provide the recumbent vehicle with a more simple and automatic leaning system, which does not require any effort by the driver.
Additionally, most recumbent cycles are uncomfortable when driving off-road. Unlike conventional bicycles, recumbent cycles do not permit the driver to lift up above the seat while driving over a rough terrain. The driver of a recumbent cycle is therefore exposed to severe vertical and side-to-side shocks. To compensate, some recumbent designs have incorporated suspension systems, such as those vehicles disclosed in U.S. Pat. Nos. 4,548,421 and 6,203,043B1. But the suspensions disclosed in these references are quite complicated. It would be advantageous to provide a recumbent vehicle with a simple suspension system.
Most of the recumbent vehicles have a bicycle-type hand-operated braking system with brake levers on the handlebars. However, braking a three- or four-wheeled cycle has some special concerns. First of all, multi-wheeled cycles are more massive and require greater braking power. Secondly, for a safe deceleration the braking force should be applied simultaneously and equally both left and right wheels. It is difficult to do with two separate hand brake levers. Using the power of only one hand for stopping two wheels can be insufficient for a strong and reliable braking of the vehicle. Disk or drum brakes are more efficient, but they are more complicated and expensive, and they create an extra load to the wheel's rim and spokes. Additionally, in order to be ready for emergency braking, the driver has to grip the handlebars at all times. It is not convenient driving when both hands are always busy. It would be advantageous to provide a recumbent cycle with leg-operated, back pedaling brakes with ordinary calipers.
The steering mechanism of the majority of the recumbent vehicles has a bicycle-type front or lowered handlebars, for example U.S. Pat. Nos. 4,432,561, 5,145,196, 5,263,732, 5,544,906, 5,568,935, 6,203,043B1 and 6,402,174B1. A common disadvantage of these cycles is the low ratio of the steering mechanism, usually about 1, i.e. the angle of turning of the bar is approximately equal to the relevant angle of turning of the steered wheel. It provides overly sensitive control of the vehicle and requires continuous attention by the driver, especially at a high speed. Also, compared to a bicycle, driving recumbent tricycle is affected by forces intending to turn the vehicle right or left. Those forces appear, for example, when the vehicle drives on a lateral slope, when road obstacles decelerate only one of the side wheels, or when the braking of side wheels is not synchronous. These forces create a turning torque to the steered wheel (or wheels), which is transmitted without any reduction (due to low ratio) to the handlebars. This requires an additional effort by the driver to hold the bars to keep the desired direction. For easy and comfortable driving it would be advantageous to provide a recumbent vehicle with a car-style steering mechanism with a high-ratio reducer.